The hills of the Sacromonte
are sedimentary deposits consisting of clay, round boulders and pebbles
which vary in size from a few centimetres to one or two metres. They
were originally created approximately eight million years ago in the
miocene period as a consequence of large streams of water which dragged
the rocks from the Sierra Nevada mountain range until they eventually
came to rest on the plains of the Vega. The walls of the caves in the
Sacromonte are the end product of the displaced mud and rocks which
have fossilised over the passage of time.